Apple I for Apple II
Here is a program to run the Apple I monitor (and other Apple 1 programs with a small patch) on an Apple II.
There are patches to echo a character to the display and get a key from the keyboard. I am not sure if newlines work quite properly as I don't have an Apple I to see how these actually work. It uses HGR2 for the display so that the RAM from 0.3FFF is available.
Control L will clear the screen. Control Q will quit. Control ^ will allow you to enter control L and control Q and control ^.
To load the program, from Applesoft BASIC, go into the monitor:
Enter the program in the monitor starting at $8000:
Paste this program into an Apple II emulator or somehow copy it to a real Apple II.
replace the bytes AD 12 D0 with 20 70 80 in your Apple 1 programs. LDA $d012 becomes JSR $8070
also, replace the bytes AD 11 D0 with 20 70 80 in your Apple 1 programs. LDA $d011 becomes JSR $8070
I did this with "lunar" lander and the program worked.